package demo3;

public class Main{
    public static String fund(String str){
        StringBuilder ret = new StringBuilder();
        int[] array = new int[255];
        for(int i = 0; i < str.length(); i++){
            if(array[str.charAt(i)] == 0){
                ret.append(str.charAt(i));
                array[str.charAt(i)] = 1;
            }
        }
        return ret.toString();
    }
    public static void main(String[] args){
        Scanner scanner = new Scanner(System.in);
        String str;
        while(scanner.hasNextLine()){
            str = scanner.nextLine();
            System.out.println(fund(str));
        }
    }
/*    public void merge(int A[], int m, int B[], int n) {
        for(int i = m; i < m + n; i++){
            A[i] = B[i - m];
        }
        for(int i = 0; i < A.length - 1; i++){
            for(int j = 0; j < A.length - i - 1; j++){
                if(A[j] > A[j + 1]){
                    int tmp = A[j];
                    A[j] = A[j + 1];
                    A[j + 1] = tmp;
                }
            }
        }
    }*/
    public void merge(int A[], int m, int B[], int n) {
        int i = m - 1;
        int j = n - 1;
        int k = m + n - 1;
        while(i >= 0 && j >= 0){
            if(A[i] > B[j]){
                A[k] = A[i];
                i--;
            }else{
                A[k] = B[j];
                j--;
            }
            k--;
        }
        while(i >= 0){
            A[k] = A[i];
            k--;
            i--;
        }
        while(j >= 0){
            A[k] = B[j];
            k--;
            j--;
        }
    }
}